Decomposition of nickel-copper matte



Patented Jan. 9, 1940 UNITED STATES PATENT OFFICE nnoom-osrnon 0F NICKEL-COPPER mm Guenther Hamprechh. Ludwigshaien-on-the- Rhine, Germany, assignor to I. G. Farbenin- Y dustrie Aktiengesellschaft;\FranHoi-t-on-the- Main, Germany No Drawing. Application December 1t, 1938, Serial No. 246,062. In Germany December 20,

2 Claims.

iron and the gangue, a matte for the working up of which various proposals have been made. For example it has been proposed to treat the matte with chlorine and copper chloride solution containing such an amount of calcium chloride or sodium chloride that the cuprous chloride formed is not precipitated. The resulting solution is then worked up electrolytically to metallic copper and nickel, the initial solution thus being recovered in addition to chlorine. This processhas not been introduced in practice because the decomposition of the matte offers difficulty.

I have now found that nickel-copper matte of any composition can be decomposed in a very short time with copper chloride solution nearly completely without any need for adding calcium chloride or sodium chloride by taking care that the solution contains such an amount of nickel chloride that the cuprous chloride formed remains dissolved. The residue contains besides the sulphur content of the matte a little copper sulphide and a considerable amount of the precious metals originally contained in the matte.

The following table gives the approximate minimum amounts of nickel chloride which the solution must contain at centigrade in order that the given amounts of cuprous chloride should remain dissolved at the said temperature:

Grams of NiClz Grams oi. CuCl per liter per liter 220 80 330 170 440 225 At higher temperatures, correspondingly less amounts of nickel chloride are necessary for this Purpose.

In the working up of mattes rich in nickel, as for example those containing more than about 45 per cent of nickel, it is preferable so to select the composition of the nickel chloride-copper chloride solution acting on the matte that the ratio between nickel and copper corresponds to the ratio between the two metals present in the matte. In the case of mattes poor in nickel, care is preferably taken'that the ratio of nickel to. copper in the solution is greater than the ratio in the matte.

The new process has the great advantage that very pure solutions can be directly obtained which may be worked up for example electrolytically.

The following examples will further illustrate the nature of this invention but the invention is not restricted to these examples.

Example 1 cubic meters of a solution, warmed to 70 centigrade, of 440 grams of nickel chloride and 310 grams of copper chloride per liter are brought together with 2.67 metric tons of finely broken (or better, ground) nickel-copper matte containing 42 per cent of nickel, 47 per cent of copper and 10 per cent of sulphur into a slowly rotating inclined drum. The solution becomes heated very rapidly to 100 centigrade and already after 10 minutes the resulting solution of nickel chloride and cuprous chloride may be filtered off from the residue,'consisting mainly ofsulphur, without the occurrence of difilculty by reason of the precipi-' tation of cuprous chloride.

The solution now contains about 540 grams of nickel chloride and 300 grams of cuprous chloride per liter. It may be worked up electrolytically to metallic nickel and copper in known manner.

The initial solution is recovered in the following manner: The chlorine set free during the electrolysis of the nickel chloride is led into the nickel chloride-cuprous chloride solution partially oxidized anodically coming from the copper electrolysis and the necessary amount of nickel chloride is added to the solution in the form of dilute electrolysis waste liquor.

Example 2 40 cubic meters of a solution, warmed to 95" centigrade, of 470 grams of. nickel chloride and 190 grams of copper chloride per liter is brought together with 2.47 metric tons of finely ground nickel-copper matte containing about 56 per cent of nickel, 24 per cent of copper and 20 per cent of sulphur into a slowly rotated inclined be worked up into nickel and copper in the manner described in Example 1.

In order to recover the initial solution, the procedure described in Example 1 is followed but a special addition of nickel chloride is unnecessary in this case.

What I claim is;

1. A process for the decomposition of nickelcopper matte, which consists in using as the decomposing agent a copper chloride solution containing an amount of nickel chloride sufiicient to keep the cuprous chloride formed dissolved.

2. A process or the decomposition of nickel copper matte, which consists in using as the decomposing agent a copper chloride solution containing suficient nickel chloride to keep the cuprous chloride formed dissolved and making the ratiohetween nickel and copper in the decomposing solution equal to the ratio between the two metals present in the matte.

GUENTHER HANEPRECI-I'I. 

